A low-complexity 2-D DOA estimation algorithm for massive MIMO systems

Abstract

In this paper, we research the problem of two-dimensional (2-D) direction-of-arrival (DOA) estimation in massive multi-input multi-output (MIMO) systems and propose a 2-D DOA estimation algorithm for massive MIMO systems based on a large-scale uniform rectangular array (URA). In our algorithm, the large-scale URA is firstly divided into four smaller subarrays, including two pairs of shifted URAs. The proposed algorithm exploits the rotational invariance relations of two pairs of shifted URAs to estimate the 2-D DOAs of multiple signals. Our algorithm has a much lower computational complexity than the 2-D MUSIC algorithm, especially when the number of antennas is large. Simulation results show that the proposed algorithm provides an excellent performance that is very close to that of the 2-D MUSIC algorithm.